Hydrogenation of oxo alcohol bottoms



March 2, 1954 '.1. K. MERTzwElLLER HYDROGENTION OF' OXO ALCOHOL vBOTTOMS Filed April l, 1949 ya; ywydss" I wald/Nady@ Patented Mar. 2, 1954 HYDROGENATION OF OXO ALCOHOL BOTT-OMS Joseph K. Mertzweller signor to Standard l Baton Rouge, La., as- 1l Development Company,

a corporation of Delaware 8 Claims.

The present invention relates to the production of oxygenated organic compounds by the catalytic reaction of 'olefms with hydrogen and carbon monoxide. More specifically, the present invention presents a process for increasing the yield of alcohol that may be obtained at the expense of undesirable secondary reaction 'products resulting from this process.

It is now well known in the art that oxygenated organic compounds may be synthesized from olens by reaction of the latter with carbon monoxide and hydrogen in the presence of catalyst containing cobalt or iron in a two stage process. In the rst stage, the olelinic material, the catalyst, and proper proportions of CO and H2 are reacted to give a product which consists predominantly of aldehydes, and this material is hydrogenated in the second stage to give the corresponding primary alcohols. The over-all reaction consists essentially of an addition of H2 and CO to the unsaturated linkage and may be formulated as follows:

Stage 1.

RCH'=CH2+CO+H2L RCH2-CH2CHO Stage 42.

RCHQCHzCH'O+I-I2QRCH2CH2CH2OH It is thus seen that both the aldehyde and the alcohol formed as a result of the reaction contain one more carbon atom than the olenic material from which they are derived.

The carbonylation reaction provides a particularly effective method for preparing valuable primary alcohols, which find large markets, particularly as plasticizers. The carbonyl'ation, or 0X0 process, asl it is sometimes called, may be used eiectively with long and short chain olenic compounds, depending on the type alcohol desired. Thus straight and branch chained olens and diolehns such as propylene, butylene, butadiene, pentene, pentadiene, hexene, heptene, olen polymers such as diand tri-i'sobutylene, hexene and heptene dimers, liziolypropylenes, and oleinic fractions 'from the hydrocarbon synthesis process, thermal or catalytic cracking operations, and other sources of hydrocarbon fractions containing sucholens may be used asfstarting material, depending on vthe nature of the nal product desired. In general, olefins having up to about 18-20 carbon atoms in the molecule are preferred in this reaction.

The catalysts for the 'first 'stage of the process are usually employed in the forni of 'salts o'f the catalytically 'active metals 'with high Amolecular intermediates for detergents andl Application April 1, 1949, Serial No. 84,811

weight fatty acids such as stearic, palmitic, oleic, naphthenic and similar acids. Thus, as suitable catalysts are such organic salts as cobalt stearate, oleate, or napthenate or iron linoleate. These salts are soluble in the liquid olen feed and may be supplied to the rst reaction zone as hydrocarbon solutions or preferably, dissolved in the olehn feed.

The synthesis gas mixture fed to the first stage may consist of any ratio of H2 to CO, but preferably these two gases are present at about 1.0 volume hydrogen per volume CO. The conditions for olens reacting with H2 and CO vary somewhat in accordance with the nature of the olen feed, but the reaction is generally conducted at pressures in the range of about 15.00 to 4500 p. s. i. g. and at temperatures in the range of about to 450 F. n

The (quantity of E24-CO with respect to olefins used may vary within wide ranges, for example, from 1000 to 45,000 cu. ft. of AI-Iz-I-CC) per barrel of olefin fed. In general, about 2,500 to 15,000 cu. ft. of Hz-l-CO per barrel of olen fed are employed.

At the end of the first stage, the reaction prodmaterials are generally transferred` directly to a hydrogenation vessel, where the aldehydes are hydrogenated to alcohols. As hydrogenation catalyst may be employed such materialsassupported or unsupported metallic nickel, cobalt, sulfactive catalysts as tungsten, molybdenum and nickel suldes, alone or in combination, copper chromite, or other carbonyl group-reducing catalysts. In the hydrogenation step,vthe temperatures are generally between the range of 150450 F. and the pressures within the range of about 150G-4500 p. s. i. g.

The na1 stages of the process involve the stages that the .present invention applies. As it is performed generally in the art, the aldehydes are hydrogenated under the conditions referred to above, then the crude hydrogenation product is 'rst subjected to a distillation process to distill unreacted hydrocarbons boiling below the alcohol range, and the bottoms from this distillation, comprising the alcohol fraction, is subject to a second'distillation stage, where the alcohols are taken overhead. The bottoms'from this alcohol distillation have in the past, been con-'- sidered to be a mixture of polymeric material, such asu pol'ymerized aldehydes. and ketones, esters, high molecular weight` ethers and 'sec-'- ondary alcohols and polymerized hydrocarbons,

and such bottoms were considered to be of only secondary value as fuel. These bottoms had the effect of cutting down substantially the yield and the alcohol selectivity of the process and increase the diiculty of separating the alcohols from these bottoms.

It is the principal object of the present invention to provide a. process whereby the over-all yield and selectivity of alcohols from the carbonylation reaction is substantially increased. It is also the object of the present invention to decrease the quantity of by-products from this reaction, which only are of secondary value as fuel.

The present invention is based upon the discovery that valuable by-products can be obtained by special treatment of the bottoms remaining after removal of the main alcohol product from the total hydrogenated material. These products which include high molecular weight alcohols and ethers, are unavailable; by the processes hitherto proposed.

' As will be made more clear below, the process of the present invention is especially effective when a sulfactive hydrogenation catalyst is employed in the aldehyde product hydrogenation stage. These catalysts, such as MoSz, on active char, are somewhat less active than nickel or cobalt hydrogenation catalyst, and require somewhat higher temperatures for operation, but they have the great advantage of not being poisoned by sulfur in the feed stream nor by CO resulting from the cobalt carbonyl decomposition step, thus` obviating requirements for costly and elaborate purification steps. The present invention relates to the recovery of maximum quantities of alcohol from bottoms from the distillation process following hydrogenation in the presence of such a catalyst.

In accordance with the present invention, the acetal-containing bottoms from the alcohol distillation step are passed to a secondary hydrogenation chamber which preferably contains a more active hydrogenation cataylst than that employed in hydrogenating the first stage aldehydes product and this step is followed by pressure saponication to recover alcohols from esters, and fractionation. Hydrogenation of the heavy material is accomplished without excessive decomposition. The material from the secondary hydrogenation stage after saponication is then treated in the recovery system as shown below to recover further yields of product alcohols and also valuable higher molecular weight ethers. Thus by converting 30% of these bottoms, the overall yield may bei increased by about 6% and the overall selectivity by about 8l0%.

The present invention will be best understood from the more detailed description hereinafter, wherein reference will be made to the accompanying drawing, which is a schematic illustration of a system suitable for carrying out a preferred embodiment of the invention.

Referring now to the drawing, an olefmic hydrocarbon having one carbon atom less than the number of carbon atoms in the desired resulting oxygenated compound and containing a dissolved catalyst promoting the reaction of oleiinic compounds with carbon monoxide andhydrogen to form oxygenated organic compounds is fed to the lower portion of primary reactor I through feed line 2. Any conventional type catalyst such as `cobalt stearate, naphthenate, oleate, iron linoleate, etc., may be used. Catalyst make-up dissolved in olefin feed may be added to the main olen feed line 2 through line 3. The concentra- 75 tions of catalyst and the proportions of the catalyst-containing feed to the non-catalyst containing feed are such that the concentration of catalyst in the total olefin feed varies between 0.1 to 5.0% byvweight, preferably about 1% by weight cf catalyst salt to olefin.

Simultaneously, a gas mixture containing hydrogen and carbon monoxide in the approximate ratio of 0.5 to 2.0 volumes of hydrogen per volume of carbon monoxide is supplied through line d and is fed to primary reactor I along with the olen to be reacted. Reactor I is preferably operated at about 3000 p. s. i. g. and at a temperature of from about 250 to 400 F. The reactor may contain no packing, or may be packed with catalytically inert solid material, such as ceramic Raschig rings, pumice, and the like.

Liquid oxygenated reaction products, unreacted oleflns, and synthesis gases are withdrawn from the top of the high pressure reactor I and are transferred through line 5 and cooler 6 to high pressure separator 1 where unreacted gases are withdrawn overhead through line 8 scrubbed in scrubber 9 of entrained metal carbonyl catalyst and may be recycled through line I0 to Oxo reactor I or used as required in other parts of the system.

Liquid products are withdrawn through line I2 from high pressure separator 'I to low pressure separator I3 where more dissolved metal carbonyl and gases are removed overhead through line i4. From the bottom of low pressure separator I3 the liquid products and unreacted oleiins are passed through line i5 to catalyst removal zone I6 which may be a vessel packed with inert solid material of a nature similar to that in primary reactor I or may also contain no packing. Hydrogen-comprising gases recovered from another stage of the process may be supplied to catalyst removal zone IS through line 55 and passed through zone I5 countercurrently to the liquid oxygenated product. Catalyst removal zone I6 is preferably maintained at a temperature of about 200 to 450 F., at which temperature the catalyst which enters zone i6 predominantly in the form of metal carbonyl, such as cobalt carbonyl, dissolved in the liquid product, is decomposed into metal and carbon monoxide. The metal may be deposited on the inert packing within zone I6 or on the walls, while the carbon monoxide may be purged by the hydrogen. A mixture of hydrogen and carbon monoxide may be withdrawn through line I1 and sent to a methanizer or other suitable catalytic unit, wherein carbon monoxide may be converted into methane in any conventional manner, or the purge gas mixture may be used directly in hydrogenator I9 if a CO- insensitive hydrogenation catalyst such as the sulfactive catalysts such as sulfides of molybdenum, tungsten, etc., is employed as hydrogenation catalyst.

Liquid oxygenated products now substantially free of carbonylation catalysts are withdrawn from catalyst removal'zone i6 through line IB and passed tothe lower portion of hydrogenation reactor IS. Simultaneously, hydrogen is supplied to reactor I9 through line 20 in proportions sufficient to convert the organic carbonyl compounds in the oxygenated feed into the correspending alcohols. VHydrogenator Ie may contain a mass of any catalyst, for example, nickel, copper chrcmite, sulfactive hydrogenation catalysts such as tungsten suldc, nickel sulfide, molybdenum sulfide,

conventional hydrogenation accerta head through line 2|' from reactor I9 then.

through cooler 22 intohigh pressure separator 23. Unreacted hydrogen maybe withdrawn overhead from separator 23 through line 25 and. either vented through line" 45 or preferably recycled through line 25 to hydrogenation reactor i9; The liquid products are withdrawn from sepa'-4 rator' 23 through` line 24 into low pressure sep-` arator 20 where more dissolved gas isilashed overhead through line 4t and liquid products are withdrawn from a lower portion and passed through line 27 to hydrocarbon still 28, wherein are distilled overhead low-boiling products, most'- ly hydrocarbons boiling below the alcohol product desired. Thus when a C7 olen fraction is the feed tov the process, generally the product boiling up to 340 F. is removed as a' heads cut in hydrocarbon still 23, and this material is withdrawn overhead through line 29 and may be used asV a gasoline blending agent if desired. The 'i bottoms from this primary distillation are withdrawn from hydrocarbon still 20 through line 30 and sent toi alcohol still 3| where the product alcohols boiling in the desired range may be removed overhead by distillation at atmospheric 'ik pressures or under partial vacuum, depending upon the molecular Weight of the alcohols.

The bottoms from alcohol still 3i are withdrawn through line 33 and passed into secondary hydrogenation chamber 34. It may be desirable to include a guard catalyst section 35 in the secondary hydrogenation stage to prevent catalyst poisoning by substances likely to deteriorate the more active catalyst in the second hydrogenation stage. contains high concentrations of nickel or copper on supports such as kieselguhr or silica gel and hydrcgenation conditions depend upon the activity of the catalyst employed. Thus with a nickel catalyst, temperatures in the range of 300-400 F., hydrogen pressures of 150G-4500 p. s. i. g. and liquid feed rates of 0.4 to 2.0 v./v./hr. are preferred. With a copper or cobalt catalyst, somewhat higher temperatures may be required.

The use of a guard catalyst is particularly applicable when a sulfactive catalyst has been employed in hydrogenating the aldehydes in reactor i 9. As guard catalyst in 35, nickel or copper may be employed.

As a result of this more active hydrogenation,

a substantial portion of the acetals present in the bottom from alcohol still 3l are reduced to alcohols and ethers.

After hydrogenation, product is withdrawn through line 36 and passed to high pressure separator 3? wherein liquid hydrogenation product separates and hydrogen is taken oil overhead through line 3e for recycle to the system where desired. Product consisting essentially of alcohols,l esters, ethers and heavier unreacted material is passed through line 39 to saponiiication chamber d0. In 40, saponication of the esters present in the bottoms' is completed. An aqueous alkali solution such as sodium hydroxide or sodium carbonate from about 5 to 20% concentracycled toE the process.

The catalyst in chamber 34 preferably fi 6 tion is passed to chamber 012 through: line 4t. Chamber 40? may he.l any conventional typef oi saponicatiorr vessellequ'ipped withiclosedtor. open steam coils a'nd'- preferablyl withV a; means 01x agi# tation. The aqueous caustic admittediv through line'li il isthoroughly agitated andimixed with' the li'y'drogenationA productA and theagitated mixture of caustic and product i's' maintained at a` temperatureofv about 300 to, 500 F. andv a pressure of about 100150 400m-zestig. The* caustic treated material' after saponication is withdrawn through line 42 and'. passed to settler 43 where the bottom caustic' layer' isI withdrawn after set'.- tling throughi line-l 44' and either discarded or. re- The` upper layer compris:- ing alcohols, ethersandv unsaponiable material is withdrawn through line 4'5, passed through dryer 40 and then to the fractionation system. In tower 47 an ether product is taken overhead through' line 48'. The distillation bottoms are I withdrawn through: line 54' and passed to still 50 wherein alcohols are taken as a headsA cuts and'.

Thev system illustrated in the drawing andi in the foregoing description permits of various mod'- iiica-tions. Thus the saponication step may be omitted if desired, ii the ester content of the bottoms following the second hydrogenation step is low. On the other hand,` if hydrogenation inthe initial stage is sigi'iiicantlyr incomplete, it

may be desirable to subject the alcohol bottoms to a .mild acid hydrolysis reaction.

The invention may be further illustrated by the following examples, in which the bottoms from the distillation of a Cm olefin fraction which had been subjected to the carbonylation reaction I was' further subjected to the vprocess of the invention.

EXAMPLE I First Stuga-Aldehyde synthesis olefinfeed C7 cut (B. P. 1602210 FJ.

Catalyst, wt. perBcent in feed- 50% gibalt naphthenate.

Temperature, 40 3 Pressure, p. s. i. g 3000. Liquid feed rate, y./v./h 0.4. Hg--CQ feed rate, s. c. f./B 5000. Hg/CO ratio, vol 1 l/l.

lefn conversionpernceut: 7'5-80.

Second stage.-Hydrogenation of ald'e'hydes to alcohols Catalysthcusifu-g 10% MoSz on charcoal. Temperature', F 450. Liquid feed rate', v./v./hr

0.5. Hydrogen pressure 2700-2900.

Hydrogen rate,v c. f /B Distillatiou summary:

Vt. per cent hydrocarboii-l-uilreacted material A (init-340 F 25.1.

.Per cent alcohols (34N-370 F.) 57.5.

Wt'. per cent bottorfsf up 17.4. Alcohol selectivity, per cent 71.

A sample of bottoms resulting from the above distillation showed the following analytical inspection, as given in column A.A

A n C l al" API Gravity 34.5 I se. c l y3c. e Hy'droXylNi KOH/gm) 49 110 143 Carbonyl 33 5 3 Saponiicatiou Ni 32 27 1 Acid Numoer... 1.0i 1.2 0.o

One liter of this material was hydrogenated in a shaker autoclave at 350 F. and 2700 p. s. i. g.

7 with rhydrogenkw (9o-92%)"ior 12 hours in the presence of 10% by volume of nickel hydrogenationcatalyst on a' kieselguhr support. Column B is theinspection of the material from this hydrogenation stage.

The hydrogenated product was saponifled in a stirrer autoclave with an equal volume of 15% caustic solution at 400 F. for 5 hours. The pressure reached 250 p. s. i. g. during the saponiflcation. The saponied product was washed 3 times with hot water and dried over anhydrous sodium sulfate. The product gave the inspection tabulated in column C above.

The saponied product was subjected to distillation at mm. Hg pressure at a 3/1 reflux ratio. It was found that a saturated ether amounting to about 30 volume per cent of the original bottoms and C15-C15 alcohols also equivalent to about 30% of the bottoms were recovered. In addition, about by volume of Ca alcohols were recovered, thus making an over-all increase in selectivity to C8 alcohols of about 3%, based on a bottoms product from the first hydrogenation stage of 18%.

EXAMPLE II Run No...` l

Primary Hydrogcnation:

Operation Continuous camiyst Mos. on charcoaiff Mosfon chaman..

Avg. Temp., F Carbonyl No Bottoms H'yclrogeuation` toms:

Carbonyl No Hydroxyl No. Saponicatlou No 2 VCO-and` Hz fin the"presence'of a. `cobalt carbonylation catalyst under reaction conditions including temperatures in the range of 150 to 450 F. and pressures in the range of 1500 to 4500 pounds to produce oxygenated reaction products comprising organic carbonyl compounds in a reactionzone, passing said oxygenated reaction products to an initial hydrogenation zone, subjecting said products to a hydrogenation reaction under reaction conditions including pressures in the range of 1500 to 4500 pounds and temperatures in the range of about 150 to 500 F. to produce substantial quantities of alcohols having one or more carbon atoms than said olens, withdrawing hydrogenated and non-hydrogenated organic products from said hydrogenation zone, subjecting said products to an alcohol distillation process in an alcohol distillation zone, withdrawing overhead a product comprising substantially alcohols containing one more carbon atom than the olefin fed to the carbonylation zone, withdrawing distillation bottoms from said distillation zone, subjecting said distillation bottoms to a second hydrogenation reaction in a second hydrogenation zone under conditions more severe than in said initial hydrogenation zone, and recovering valuable alcohols from said hydrogenated material.

2. The process of claim 1 wherein the hydrogenation conditions obtaining in said initial hydrogenation zone comprise pressures in the range of 1500 to 4500 p. s. i. g., temperatures in the range of 400 to 500 F., and feed rates of 0.5 to 2..0 liquid v./v./hr.

Continuous Continuou Continuous.

s 10% MoSn 0n Charcoal. 10% MaS; On Charcoal. O 5(4)-470.

None.

1 Calculated values.

treated in accordance with the invention, using a more active catalyst in the `second hydrogenation stage. Thus Columns 2 and 4 indicate that there is no substantial overall difference in higher molecular weight alcohol obtainable when carrying out the initial hydrogenation to a low carbonyl value of 1-4 and distilling alcohol product overhead, when saponifying the bottoms (column 4), or carryingout the primary hydrogenation less completely, then hydrogenating bottoms to a low carbonyl value (column 2) under the same conditions with a catalyst of the same activity. When, however, a more active catalyst is employed in the bottoms hydrogenation process, a substantial increase in higher molecular weight alcohol product is obtained (column 1).

What is claimed is:

1. An improved process for theproduction of alcohols from olens, carbon monoxide and hydrogen which comprises contacting olens with 3. The process of claim 1 wherein a catalyst of a greater hydrogenation potential is maintained in the second hydrogenation zone than in the initial hydrogenation zone.

4. The process of claim 1 wherein the catalyst in said initial hydrogenation zone is molybdenum sulfide on an active carbon carrier, and wherein the catalyst in said second hydrogenation zone contains a member of the class consisting of nickel, cobalt, copper and molybdenum.

5. The process of claim 4 wherein the catalyst in said second hydrogenation zone comprises cobalt.

6. The process of claim 4 wherein the catalyst in saidsecond hydrogenation zone comprises copper.

'7. The process of claim 1 which comprises passing said hydrogenation products from said second hydrogenation zone to a saponication zone, subjecting said products to a saponication reaction under superatmospheric pressures and recovering increased yields of valuable oxygenated products.

`8. The process of claim 7 wherein pressures in said saponicatio about 100 to 400 p. s. i. g.

JOSEPH K. MERTZWE'ILLER.

Number UNITED STATES PATENTS Name Date Adkins et al Aug. 31, 1937 Joshua et a1 Sept. 28, 1937 Jones Mar. 29, 1938 Ipatiei et a1. Jan. 31, 1939 Woodhouse June 18, 1940 Pier et al. Aug. 17, 1943 Roelen Aug. 17, 1943 Doumani Oct. 31, 1944 n zone are in the range of Number National Petroleum News: vol. 37, No. 4

l0 Name Date Gresham et a1 June 18, 1946 Sen'sel et al. Jan. 14, 1947 Boucher et al Aug. 26, 1947 Roland et a1. Dec. 23, 1947 Gresham et a1 Sept. 14, 1948 Voorhies Dec. 7, 1948 Harlan, Jr. Apr. 18, 1950 Owen May 30, 1950 Hoog et a1 May 30, 1950 Parker Apr. 29, 1952 CTI-IER REFERENCES 5, sec.

15 2, Nov. 7, 1945, pages R-926, R-928, R-930. 

1. AN IMPROVED PROCESS FOR THE PRODUCTION OF ALCHOLOS FROM OLEFINS, CARBON MONOXIDE AND HYDROGEN WHICH COMPRISES CONTACTING OLEFINS WITH CO AND H2 IN THE PRESENCE OF A COBALT CARBONYLATION CATALYST UNDER REACTION CONDITIONS INCLUDING TEMPERATURES IN THE RANGE OF 150* TO 450* F. AND PRESSURES IN THE RANGE OF 1500 TO 4500 POUNDS TO PRODUCE OXYGENATED REACTION PRODUCTS COMPRISING ORGANIC CARBONYL COMPOUNDS IN A REACTION ZONE, PASSING SAID OXYGENATED REACTION PRODUCTS TO AN INITIAL HYDROGENATION ZONE, SUBJECTING SAID PRODUCTS TO A HYDROGENATION REACTION UNDER REACTION CONDITIONS INCLUDING PRESSURES IN THE RANGE OF 1500 TO 4500 POUNDS AND TEMPERATURES IN THE RANGE OF ABOUT 150* TO 500* F. TO PRODUCE SUBSTANTIAL QUANTITIES OF ALCOHOLS HAVING ONE OR MORE CARBON ATOMS THAN SAID OLEFINS, WITHDRAWING HYDROGENATED AND NON-HYDROGENATED ORGANIC PRODUCTS FROM SAID HYDROGENATION ZONE, SUBJECTING SAID PRODUCTS TO AN ALCOHOL DISTILLATION PROCESS IN AN ALCOHOL DISTILLATION ZONE, WITHDRAW- 